This invention involves a substantial departure from current art, using natural forces to purify sewage or other tainted water by impounding it under conditions which permit those forces to work with unique effectiveness. When the water is sufficiently pure, it can be reused or released benignly into the hydrological cycle.
The increasing knowledge of the vulnerability and importance of clean water supplies require that sewage and other contaminated waste water not be dumped into the environment without treatment to mitigate or eliminate its adverse impact. The use of contaminated water for processing and/or household may also require pretreatment or purification.
Historically, water purification has taken advantage, in some cases, of aerobic or anaerobic biological devices to produce improved effluent using biota fixed on a substrate, or suspended. Anaerobic devices have traditionally been limited to a maximum of about 70%-80% treatment and proposed as polishing stages prior to some further action, as in E. J. Jordan's (U.S. Pat. No. 3,950,252 4/1976 & 4,211,655 7/1980), A. A. Monson's (U.S. Pat. No. 4,162,976 7/1979), and A. W. Green's (U.S. Pat. No. 4,293,421 10/1981).
Aerobic devices, which are more biologically efficient than anaerobic ones and can produce complete treatment, suffer from the requirement of the use of various powered mechanisms to mix effluent with air and as a result are relatively expensive and unreliable, often requiring the use of disinfection which chemically repollutes the treated effluent. When used for sewage treatment, they frequently are not maintained properly releasing a low grade effluent resulting in environmental damage.
This invention, by contrast, advances the technology an order of magnitude by achieving reliable, cheap and complete treatment without mechanical or powered components. It permits higher efficiency, a 4-5 log reduction in sewage fecal coliform bacteria, a 99+% removal of biological oxygen demand and suspended solids, plus substantial reduction in other organic and inorganic solutes. It is driven by a hydraulic static head of but several inches. It can produce limpid, odorless water that can be reused.
This device is inexpensive to install and requires no normal maintenance. It can conveniently be installed under a lawn, building or parking area. It requires no separation from surface water, wells or property lines. Its products can be used for decorating ponds, fountains or irrigation.